目的：结缔组织生长因子（CTGF）是一种重要的参与肾纤维化的细胞因子，为了进一步阐明外源性CTGF的作用机制，该文探讨了外源性CTGF对人肾小管上皮细胞胶原Ⅲ合成中的作用。方法：将体外培养的人肾小管上皮细胞HK2 分为3组：①对照组；②CTGF小剂量组（终浓度为2.5 ng/mL）；③CTGF大剂量组（终浓度为20 ng/mL）。用倒置显微镜观察细胞形态变化，RT-PCR检测HK2细胞胶原Ⅲα mRNA水平的变化，免疫组织化学方法观察HK2 细胞胶原Ⅲα的表达。结果：不同浓度的CTGF作用于HK2 细胞48 h后，均可使HK2 细胞由椭圆形变为梭形。大剂量CTGF刺激HK2 细胞48 h后胶原Ⅲα mRNA水平显著升高（P<0.05），大剂量CTGF组HK2 细胞胞浆表达胶原Ⅲα也显著增加（P<0.05）。结论：CTGF在体外能够诱导人肾小管上皮细胞发生形态改变，大剂量的CTGF刺激可以增加人肾小管上皮细胞胶原Ⅲ的合成。

OBJECTIVE: To explore the role of exogenous connective tissue growth factor (CTGF) in the collagen Ⅲ synthesis of human renal tubular epithelial cell line HK2 in vitro. METHODS: Cultured HK2 cells were randomly assigned to three groups: placebo-control, low-dose CTGF-treated (2.5 ng/mL) and high-dose CTGF-treated groups (20 ng/mL). Cell morphological changes were observed under an inverted microscope. Collagen Ⅲα mRNA expression was detected using RT-PCR. Immunohistochemistry staining was used to assess the levels of intracellular collagen Ⅲα protein. RESULTS: After 48 hrs of low-or high-dose CTGF treatment, the appearances of HK2 cells were changed from oval to fusiform. High-dose CTGF treatment increased collagen Ⅲα mRNA expression (0.4461±0.0274 vs 0.2999±0.0115;P<0.05) as well as the protein expression of collagen Ⅲα (0.4075±0.0071 vs 0.3503±0.0136; P<0.05) compared with the placebo-control group. CONCLUSIONS: CTGF can induce morphological changes of human renal tubular epithelial cells in vitro. High concentration of CTGF may increase the synthesis of collagen Ⅲα.